The present invention relates to a semiconductor driver circuit for driving an electroluminescent device through an electrode and to a display device with the semiconductor driver circuit and further to a method for adjusting brightness balance of a display element in the display device.
A display device with a display element that includes pixels made of electroluminescent devices generally has data electrodes and scanning electrodes. The word of “EL” means “electroluminescent” in the following description. The data electrodes and the scanning electrodes intersect with each other, and the EL device is connected to both the data electrodes and the scanning electrodes at each intersection. For example, the data electrodes are connected to output bumps of a semiconductor data driver circuit.
Now referring to FIG. 6, the diagram illustrates one of a conventional semiconductor data driver circuit 91. The semiconductor data diver 91 includes an input circuit 92. A plurality of constant-current driver circuits 93 is connected to the input circuit 92 through electric wirings, which are not shown in the drawing. Data electrodes 95 are made of transparent material and are located on the visible side of the EL device. The output bumps 94 are arranged in a row near the display element in the semiconductor data driver circuit 91.
An unwanted feature is that, if an image needs to be displayed in high resolution by the display device, the number of pixels in the display element needs to be increased. As the number of pixels increases, the number of data electrodes 95 for driving the pixels also increases. Accordingly, the size of a chip is enlarged so that the cost may rise. To avoid enlarging the size of the chip, a distance between the coadjacent data electrodes 95, that is, a distance between the coadjacent output bumps 94 needs to be shortened. However, when the output bumps 94 are arranged in a single row, the distance between the output bumps 94 cannot be shorter than the width of the constant-current driver circuit 93. The width of the constant-current driver circuit 93 cannot be smaller due to a structure of the circuit 93. This prevents the image from being displayed in high resolution. Therefore, there is a need for a semiconductor driver circuit and a display device that allow a distance between the electrodes to be shortened and also allow the area of a chip to be easily reduced, and in addition there is a need for adjusting brightness balance of a display element in a display device.